Remove the hack used to get the `runtimeType` without using an additional class in `key.dart` by AbdeMohlbi · Pull Request #178219 · flutter/flutter

AbdeMohlbi · 2025-11-09T20:09:13Z

some context :
#33297 suggested that Type literals should support generics which means that this would become a valid syntax Type type = List<int>;.
the hack used here directly references to that issue :

flutter/packages/flutter/lib/src/foundation/key.dart

Lines 109 to 120 in 2981516

    
               // The crazy on the next line is a workaround for 
        
               // https://github.com/dart-lang/sdk/issues/33297 
        
               if (runtimeType == _TypeLiteral<ValueKey<T>>().type) { 
        
                 return '[$valueString]'; 
        
               } 
        
               return '[$T $valueString]'; 
        
             } 
        
           } 
        
           class _TypeLiteral<T> { 
        
             Type get type => T; 
        
           }

because something like :

Type type = List<int>;
typedef MakeNullable<T> = T?;
typedef TypeOf<T> = T;

was not a valid syntax at the time of writing key.dart
since that issue is closed and those are valid syntax now , it is safe to remove this hack and use what @lrhn suggested in this comment

typedef TypeOf<T> = T;

in other words , before:

if (runtimeType == _TypeLiteral<ValueKey<T>>().type) {
}

class _TypeLiteral<T> {
  Type get type => T;
}

after:

if (runtimeType == _TypeOf<ValueKey<T>>) {
}

typedef TypeOf<T> = T;

Pre-launch Checklist

I read the Contributor Guide and followed the process outlined there for submitting PRs.
I read the Tree Hygiene wiki page, which explains my responsibilities.
I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
I signed the CLA.
I followed the breaking change policy and added Data Driven Fixes where supported.
All existing and new tests are passing.
I listed at least one issue that this PR fixes in the description above.
I updated/added relevant documentation (doc comments with ///).
I added new tests to check the change I am making, or this PR is test-exempt.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the gemini-code-assist bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

flutter-dashboard · 2025-11-11T11:55:08Z

It looks like this pull request may not have tests. Please make sure to add tests or get an explicit test exemption before merging.

If you are not sure if you need tests, consider this rule of thumb: the purpose of a test is to make sure someone doesn't accidentally revert the fix. Ask yourself, is there anything in your PR that you feel it is important we not accidentally revert back to how it was before your fix?

Reviewers: Read the Tree Hygiene page and make sure this patch meets those guidelines before LGTMing. If you believe this PR qualifies for a test exemption, contact "@test-exemption-reviewer" in the #hackers channel in Discord (don't just cc them here, they won't see it!). The test exemption team is a small volunteer group, so all reviewers should feel empowered to ask for tests, without delegating that responsibility entirely to the test exemption group.

stuartmorgan-g · 2025-11-11T11:55:26Z

test-exempt: code refactor with no semantic change

…n additional class in `key.dart` (flutter/flutter#178219)

@lrhn

…onal class in `key.dart` (flutter#178219) some context : [flutter#33297](dart-lang/sdk#33297) suggested that `Type literals should support generics` which means that this would become a valid syntax `Type type = List<int>;`. the hack used here directly references to that issue : https://github.com/flutter/flutter/blob/2981516d74bc2b3307a7386e7be906602b65cf22/packages/flutter/lib/src/foundation/key.dart#L109-L120 because something like : ```dart Type type = List<int>; typedef MakeNullable<T> = T?; typedef TypeOf<T> = T; ``` was not a valid syntax at the time of writing `key.dart` since that issue is closed and those are valid syntax now , it is safe to remove this hack and use what @lrhn suggested in this [comment](dart-lang/sdk#33297 (comment)) ```dart typedef TypeOf<T> = T; ``` in other words , before: ```dart if (runtimeType == _TypeLiteral<ValueKey<T>>().type) { } class _TypeLiteral<T> { Type get type => T; } ``` after: ```dart if (runtimeType == _TypeOf<ValueKey<T>>) { } typedef TypeOf<T> = T; ``` ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. - [ ] I listed at least one issue that this PR fixes in the description above. - [ ] I updated/added relevant documentation (doc comments with `///`). - [ ] I added new tests to check the change I am making, or this PR is [test-exempt]. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md --------- Co-authored-by: Victor Sanni <victorsanniay@gmail.com>

@lrhn

…onal class in `key.dart` (flutter#178219) some context : [flutter#33297](dart-lang/sdk#33297) suggested that `Type literals should support generics` which means that this would become a valid syntax `Type type = List<int>;`. the hack used here directly references to that issue : https://github.com/flutter/flutter/blob/2981516d74bc2b3307a7386e7be906602b65cf22/packages/flutter/lib/src/foundation/key.dart#L109-L120 because something like : ```dart Type type = List<int>; typedef MakeNullable<T> = T?; typedef TypeOf<T> = T; ``` was not a valid syntax at the time of writing `key.dart` since that issue is closed and those are valid syntax now , it is safe to remove this hack and use what @lrhn suggested in this [comment](dart-lang/sdk#33297 (comment)) ```dart typedef TypeOf<T> = T; ``` in other words , before: ```dart if (runtimeType == _TypeLiteral<ValueKey<T>>().type) { } class _TypeLiteral<T> { Type get type => T; } ``` after: ```dart if (runtimeType == _TypeOf<ValueKey<T>>) { } typedef TypeOf<T> = T; ``` ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. - [ ] I listed at least one issue that this PR fixes in the description above. - [ ] I updated/added relevant documentation (doc comments with `///`). - [ ] I added new tests to check the change I am making, or this PR is [test-exempt]. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md --------- Co-authored-by: Victor Sanni <victorsanniay@gmail.com>

@lrhn

…onal class in `key.dart` (flutter#178219) some context : [flutter#33297](dart-lang/sdk#33297) suggested that `Type literals should support generics` which means that this would become a valid syntax `Type type = List<int>;`. the hack used here directly references to that issue : https://github.com/flutter/flutter/blob/2981516d74bc2b3307a7386e7be906602b65cf22/packages/flutter/lib/src/foundation/key.dart#L109-L120 because something like : ```dart Type type = List<int>; typedef MakeNullable<T> = T?; typedef TypeOf<T> = T; ``` was not a valid syntax at the time of writing `key.dart` since that issue is closed and those are valid syntax now , it is safe to remove this hack and use what @lrhn suggested in this [comment](dart-lang/sdk#33297 (comment)) ```dart typedef TypeOf<T> = T; ``` in other words , before: ```dart if (runtimeType == _TypeLiteral<ValueKey<T>>().type) { } class _TypeLiteral<T> { Type get type => T; } ``` after: ```dart if (runtimeType == _TypeOf<ValueKey<T>>) { } typedef TypeOf<T> = T; ``` ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing. - [ ] I listed at least one issue that this PR fixes in the description above. - [ ] I updated/added relevant documentation (doc comments with `///`). - [ ] I added new tests to check the change I am making, or this PR is [test-exempt]. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md --------- Co-authored-by: Victor Sanni <victorsanniay@gmail.com>

…n additional class in `key.dart` (flutter/flutter#178219)

Update key.dart

a4d95af

github-actions Bot added the framework flutter/packages/flutter repository. See also f: labels. label Nov 9, 2025

AbdeMohlbi added 2 commits November 10, 2025 15:42

Merge branch 'master' into experiment

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remove comments about the used hack

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AbdeMohlbi changed the title ~~WIP~~ Remove the hack used to get the runtimeType without using an additional class Nov 11, 2025

AbdeMohlbi marked this pull request as ready for review November 11, 2025 11:49

AbdeMohlbi changed the title ~~Remove the hack used to get the runtimeType without using an additional class~~ Remove the hack used to get the runtimeType without using an additional class in key.dart Nov 11, 2025

Piinks requested a review from victorsanni November 11, 2025 23:13

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Merge branch 'master' into experiment

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Remove the hack used to get the `runtimeType` without using an additional class in `key.dart`#178219

Remove the hack used to get the `runtimeType` without using an additional class in `key.dart`#178219
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	// The crazy on the next line is a workaround for
	// https://github.com/dart-lang/sdk/issues/33297
	if (runtimeType == _TypeLiteral<ValueKey<T>>().type) {
	return '[$valueString]';
	}
	return '[$T $valueString]';
	}
	}

	class _TypeLiteral<T> {
	Type get type => T;
	}

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